Botox (onabotulinum toxin A) injection, better known as a wrinkle-buster, is not just a vanity treatment. Since hitting the cosmetic market in 2002, Botox has been used in a variety of medical applications.

Some of the FDA-approved medical uses of Botox include, blepharospasm (spasm of the eyelids), cervical dystonia (severe neck muscle spasms), severe primary axillary hyperhydrosis (excess sweating), spasticity in flexor muscles of the elbow, wrist and fingers, chronic migraine headache in adults and neurogenic urinary incontinence. Now add to that, a new medical finding.

A study conducted by researchers from Baylor College of Medicine in Houston has revealed that Botox injections may help treat refractory filamentary keratitis, a chronic corneal condition. This disorder, most commonly related to dry eye syndrome, is characterized by threadlike strands attached at one or both ends to the cornea in patients' eyes.

Patients with filamentary keratitis resistant to conventional medical therapy who were enrolled in the study were injected onabotulinumtoxinA injection (10 U/0.1 mL) subcutaneously in their eyelids. Ocular surface findings, symptom improvement, and the number and location of filaments before and after the injections were recorded.

In all patients, there was an objective and subjective improvement after the initial onabotulinumtoxinA injection. Out of the 33 eyes treated with onabotulinumtoxinA injection for filamentary keratitis, the filaments were completely resolved in 29 eyes (88%). There was partial improvement in 3 treated eyes while the filaments resolved after initial and subsequent injections but recurred within 8 weeks of each injection in 1 treated eye.

Although only 1 onabotulinumtoxinA injection was needed to bring about a sustained improvement in the filamentary keratitis condition in 14 eyes, additional injections were necessary in 19 eyes during the follow-up period because of the recurrence of symptoms and filaments on the cornea, according to the study.

Based on the study results, researchers have concluded that onabotulinumtoxinA injection should be considered an effective option for treating refractory filamentary keratitis. Given the likelihood of recurrence, serial onabotulinumtoxinA injections may be necessary in some cases, noted the researchers.

The market leader of Botox is Irvine, California-based Allergan Inc., and it rakes in over a billion dollars in Botox sales annually.

The study was published in the April issue of the journal Archives of Ophthalmology.